Neurotransmitters:
and all things synaptic
Verywell Mind defines a neurotransmitter is defined as a chemical messenger that
carries, boosts, and balances signals between neurons, or nerve cells, and other cells in the body. These chemical messengers can affect a wide variety of both physical and psychological functions including heart rate, sleep, appetite, mood, and fear.
Neurotransmitters play a critical role in human existence at the synaptic level. There are seven major neurotransmitters: acetylcholine, dopamine, gamma-aminobutyric acid (GABA), glutamate, histamine, norepinephrine, and serotonin.
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**For the sake of this project, there will be a focus on serotonin.**
Serotonin
Serotonin (or 5-hydroxytryptamine) is a neurotransmitter commonly known for regulating mood and social behavior, appetite and digestion, sleep, memory, and sexual desire and function.
Serotonin is found in both the brain (in the Raphe Nuclei in the brain stem) and the GI Track (digestive tract).
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Serotonin is often connected with depression and anxiety. Today, most antidepressants are some form of Selective Serotonin Reuptake Inhibitors or SSRI.
How SSRIs Work
SSRIs treat depression by increasing levels of serotonin in the brain. SSRIs block the reabsorption (reuptake) of serotonin into neurons. This makes more serotonin available to improve the transmission of messages between neurons.
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SSRI inhibits the reabsorption of serotonin because they have an affinity for the transporters where serotonin is reabsorbed.
Serotonin Receptors:
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There are 7 known types of serotonin receptors, with a total of 15 subcategories.
Of these 7: 6 are G-protein receptors and the other is a ligand-gated ion channel.
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The majority of the 15 known receptors for serotonin have been implicated with depression. However, the serotonin 1A (5-HT 1A) and 1B (5-HT 1B) receptors are among the most studied according to the National Center for Biotechnology Information.
GPCR from 0:51-1:25
G-Protein Coupled Receptors:
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To put it simply, a G-protein coupled receptor (GPCR) is a multi-step receptor.
First, serotonin binds to the receptor site.
After this, the G-protein is activated. From here the G-protein can activate an ion-gated channel or other internal responses